1. Field of the Invention
The invention relates to a photographic film assemblage having means for retrieving a leading end of a strip of film from within a film cassette.
2. Description of the Prior Art
The present invention relates to a photographic film assemblage of the type including a film cassette having an exit through which a leading end of a strip of film is adapted to extend to the exterior of the cassette and, more particularly, to such an assemblage which includes means for retrieving such leading end should it be inadvertently, or otherwise, moved to a position within the film cassette.
Among amateur and professional photographers, one of the most popular film formats in the 35 millimeter size. In the 35 millimeter system, the film is normally carried on a spool within a lighttight cylindrical cassette. The spool is driven at the end of the cassette and the film passes through an exit in the cylindrical wall of the cassette. The facing edges of the exit are provided with black plush to provide a light seal when nothing is passing through the exit. The light seal is improved further because the height of the exit is small to minimize light passage.
This system has the disadvantage that, when the cassette is to be removed from the camera, the film must be wound back into the cassette to avoid exposure to light. Most 35 millimeter cameras do not provide any accurate method of winding up the film without causing the end of the film (the leader) to pass through the exit into the cassette. Once the leader is in the cassette, it is very difficult to retrieve it in order to process the film or use any unexposed portions.
This loss of the leader occurs in two very different situations. When the roll of film is completely used, the film is wound back into the cassette, and it is desirable to have the leader available to remove the film from the cassette for processing. If the leader is not available, the cassette can be broken open to allow removal of the film. While this approach can be somewhat difficult and inconvenient for both the amateur and commercial processor, it is a variable solution. The leader is also lost in the suitation where the photographer has partially used a roll of film and desires to change to another type of film. The photographer must return the original film to the interior of the cassette; and, in doing so, the leader is often lost. If the photographer does not wish to waste the remainder of the original roll of film, he must somehow retrieve the leader. He may, of course, break open the cassette, which must be done in a dark room, but in the process, often ruins the cassette so that the film cannot be used without obtaining a new cassette.
Some have attempted to obviate this problem by preventing the end of the film from being fully rewound into the film cassette in the first place. For example, the film cartridges disclosed in U.S. Pat. Nos. 3,695,160 and 3,705,696 are each provided with a filmstrip having an integrally-molded projection, which is adapted to enter a perforation in the trailing end of a filmstrip to thereby preclude its entry into a take-up chamber. See also U.S. Pat. Nos. 4,145,133 and 4,212,527, wherein the leading end of a filmstrip is disfigured in a manner to preclude its entry into a film cassette. While these proposed solutions may have certain attributes, they are subject to the criticism that they may result in the filmstrip being torn, or otherwise damaged, if one were to continue to try to rewind the filmstrip after it had been stopped; and, such continued rewinding may damage the rewinding mechanism of the camera in which the film is located.
Others have recognized the value of being able to retrieve the leading end of the film without ruining the film, the cassette and/or the camera. For example, U.S. Pat. No. 3,261,237 describes a tool which can reach into the film cassette and retrieve the leading end of the film. U.S. Pat. Nos. 3,864,993 and 4,047,653 describe similar tools. However, these tools require proper manipulation and are subject to being misplaced in the workshop.